lkml.org 
[lkml]   [2018]   [Dec]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectProblem with late AMD microcode reload/feedback
Hi,

I'm trying to reload AMD Ryzen Mobile (fam17h) microcode doing:
echo 1 > /sys/devices/system/cpu/microcode/reload

The problem is I don't get any feedback. No error for the "echo"
command, no a single new line in the "dmesg". I have no idea if
microcode has been reloaded or not.

I did a quick pr_info based debugging and I noticed that:
1) load_microcode_amd() calls __load_microcode_amd() and gets UCODE_OK
2) load_microcode_amd() calls find_patch(0) and gets a NULL

because of that NULL load_microcode_amd() doesn't return UCODE_NEW.

Seeing above I've decided to debug find_patch(). It seems to be
calling __find_equiv_id(0) which returns 0.

The last step was debugging __find_equiv_id() and find_equiv_id(). It
seems that find_equiv_id() gets sig 8458000 that doesn't exists in the
equiv_cpu_table:
[19.736770] microcode: [find_equiv_id] sig:8458000
[19.736772] microcode: [find_equiv_id] equiv_table->installed_cpu:8392466
[19.736775] microcode: [find_equiv_id] equiv_table->installed_cpu:8392578

Has my microcode been updated? Is there a way to improve that
microcode loading code? Is find_patch(0) returning a NULL expected or
maybe a bug?

--
Rafał

\
 
 \ /
  Last update: 2018-12-16 00:46    [W:0.060 / U:2.920 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site